Field of the Invention
This invention relates to injection devices and in particular, but not exclusively, to injection devices of the type where a syringe is disposed in an elongate housing and a shroud element moves forwardly relative to the syringe after use to shroud the needle and thereby minimise the risk of accidental needle stick injuries.
It is important for the latching mechanism to be highly reliable and to have latch characteristics that do not alter significantly during long term storage, for example due to changes in spring characteristics, plastic creep etc, especially if the injection device is reusable. The prior art contains many examples of devices where the shroud element is latched out by snapping past a flexible plastic finger or the like. We have devised an alternative to such devices where a magnetic force is used to enable the latch.